Safety device for punch presses or the like



' Aug. '26, 930 at. J. NORDQUIST El AL 1,773,349 I I I SAFETY DEVICE FOR PUNCH PRESSES QR THE LIKE Filed Oct. 11, 1924 5 Sheet s-Sheet 1 INVENTOR., y W 7 W1 y\ A ZTORNE y Aug. 26; 1930. R E NQRDQUI-ST AL 1,773,849

SAFETY DEVICE FOR PUNCH PRESSES OR THE LIKE Filed Oct. 11, 1924 5 Sheets-Sheet 2 ATTORNLY Aug. 26,1930. R. E. J. NORDQUIST ET AL 1,773,849 1 SAFETY DEVICE FOR PUNCH PRESSES OR THE LIKE I Filed Oct, 11, 1924 3 Sheets-Sheet 3 W TTORNEY Patented Aug. 26, 1930 UNITED STATES P ATENTSeF'FJC E RONALD E. J. NORDQUIST, oE MAPLEWOOD,;-NEW JERSEY, nun menus E. :WIDELL, or CINCINNATI, 01110, ASSIGNOBS TO AMERICAN CAN comranm OF NEW Yonx,

N. Y., A CORPORATION oF-NEw JERSEY SAFETY DEVICE EoR PuucH PREssEs on THE LIKE Applicationfiled October 1 1, 1924. serial at. 742,982.

This invention relates to safety devices for punch presses or like machines, andhas for" a primary object the provision of means for.

automatically terminating the operation of 6 the machine in the eventthat two or more blanks are fed simultaneously to the operating elements.

The blank feeding mechanism, upon certain types of punch resses, consists of a re- 10 ciprocable feeding ar and suction means adapted to separate the blanks from a stack.

and position them in the zone of action of said feeding bar. It sometimes happens, in the,

able damage may result. We are, aware that heretofore certain devices have been invented for obstructing the further movement of the feeding mechanism under f such conditions. The present invention, however, contemplates the provision of means for completely stopping the operation of the press when surplus blanks are advanced by the feeding mechanism and to this end, a detecting station is provided in the path of the blanks and mechanism provided for disengaging the. clutch by which the machine is connected to its source of power in theevent that more than one blank is advanced at onetime to the detecting station,

A furtherob eCt, of the invention is the provision of an automatic detector and safety a control of this character which will'betensitive in action and simple in construction and willrequire a minimum number of. moving parts likely to require frequent repair or re- I I p x p v I p roller is held 1 n contact withthe eameby placement.

Numerous other objects and advanta es of i the invention will be apparent as it is better understood vfrom the following description, which, taken in connection with the accom panying drawings, discloses a preferred embodiment thereof. v

Referring to thedrawings,

Fi ure 1 iszaside elevation of a"stendard 5o punc anism provided by our lnvention;

7 means of a connecting rod 43.

press, equipped withthe safety mech -l "Fi 2 is afront 'elevation of the machine; and ig.i'3 "is' an enlarged fragmentarysectional'view taken along thecent'er line ofthe machine. x v Y i T he pressit'self is of standard construction and need not be described in detail. Iteomprises'p'r'imarily side frames 11, connected together by tie-rods 12 and supportinga ir'iain frame 13, which is secured thereto by means of bolts 14 and 15, k the latter extending through slots 16 in the 'sideframes 11,whereby the-angularity of the main immensity be adjusted. Said main framecarries, in the upper 'art'thereof, a main drive-"shaftll uponw i'ch is mounted a drive pulley 18 an' a standard clutch'mecha'nism 19 by'which the shaft is connected to: the power; A; slide 21, movable in guidewa'ys'22,is operated by an eccentric upon'said shaft l7' an'd carries apunch, or active die inember23, adapted to cooperate with a fixeddie 24's 1p'ported at the'punchi'ng station by a bolster plate 25 to which is secured an extension frame 2 6, -which provides a support for the blank feeding mechanism, as will hereinafter appear.

A stack-holder, consisting of vertical guide members '27 anda blank directing'port 28, is mountedupon the top of the extension frame 26. The blanks 29'are supported by 'ineans of supporting fingers'Bl, extending into the port 28, and are adapted to be drawndewn singly by means of a suction member 32, pivoted at 33 onjthe frame and carryifi asuction cup 34,;connected by atube 35. to ayacuum'tank or the like (not shown). Said'suc tion member3 2i s ada ted to bereciproca'ted vertically bymea-ns o a cam 36 actingupon a cam following'roller 37 carried upon a'rearward extension 38 of said member 32. \Said means'of a spring .39, wound aroundthe pivot 33', and: the camis given rocking 'motion by means, offa" rock shaft 41, to 'whichdt is secured, said shaft carrying at its outer 'end a crank arm 42, connected with the shaft-1'7 by s theQsucti 'nmember 32 is' rai sed fand lowered said cam 36, the suction 34 engages the blanks 29, successively and under normal 'con ditions, deposits them singly upon a reciprocating feed bar 44, mounted in guideways 45 beneath the stack holder. Said feed bar is provided with spaced spring supported fingers 46, adapted to engage behind the blanks and advance them with a step motion to the die members 23 and 24. Said bar 44 is adapted to be reciprocated by means of a lever 47, pivoted at 48 in a frame part 49 secured to the frame extension 26, said lever 47 being connected by a link 51 with a depending lug 52 at the rear of the feed bar 44 and being connected by a connecting rod 53 with the cam 36. In this manner, reciprocating motion is imparted to said feed bar from the rock shaft 41.

As the blanks are advanced by said feed bar 44, they are moved past a detecting station, shown clearly in Fig. 3 of the drawings. At this station, the blanks are held down by means of a spring-held pressure shoe 54, and are adapted to engage an adjustable detecting stud 55, disposed at predetermined distance above the feed bar 44. Said stud projects from a socket member 56, which is mounted upon a short shaft 57, having bearings in side brackets 58 secured to the top of the frame 26. The stud 55 is engaged by the front edge of the advancing blank and slightl raised in the direction of the arrow, as indicated in Fig. 3. As will hereinafter appear, the motion impartedto said stud 55 by a single blank is not sufficient to affect the operation of the machine, but if two or more blanks are advanced simultaneously, or in overlapped relationship by the bar 44, the increased motion of the additional lifting of the stud 55, disconnects the machine from the power and stops the operation thereof, as will now be described.

Referring now to Fig. 1, it will be noted that the shaft 57 carries at its outer end an arm 59, which has a spring connection, as indicated at 61, with a rod 62, connecting at its opposite end with a pawl 63. Said pawl is pivoted at 64 to a lever 65, loosely mounted upon the shaft 41. Said lever is connected by means of a link 66 to an arm 67, mounted on a transverse shaft 68, having bearings in the frame part 49. A lever 69, secured to the opposite end of said shaft 68, connects the latter with a connecting rod 71, which, at its lower end, is secured to a bell crank lever 72, pivoted at 73 to a bifurcated member 74 secured to one of the tie-rods 12.

A foot lever 75 is pivotally connected at 7 6 to the frame and is normally held in raised position by means of a spring 77, connected at one end thereto and at the opposite end to a fixed part of the frame, as indicated at 78. Said lever is connected by means of a rod 79 with a standard clutch releasing member 81, so that when the lever is depressed, the clutch is engaged and the machine connected to the power.

A downwardly extending arm 82, upon the lever 72, is provided with a notch 83 adapted to engage the lever 75 to hold the latter in lowered position, after it has been depressed. To release said lever and cause the clutch to be thrown out, the arm 82 is moved to one side manually, or, under certain circumstances, automatically, whereupon the spring 77 restores said foot lever to normal raised position.

A ratchet 84 is rigidly secured to the shaft 41 and is provided with a notch 85 adapted to engage the pawl 63 when the latter is moved downwardly to a sufficient extent, this movement, as heretofore explained, being produced by the presence of surplus blanks in the feeding mechanism. The thickness of two or more blanks beneath the stud 55 is suflicient to move said pawl into position to be engaged by the ratchet 84 and the rocking motion of the latter with the shaft 41, imparted through said pawl 63, the lever 65, link 66, arm 67, shaft 68, arm 69 and rod 71, throws the lever arm 82 out of engagement with the foot lever 75, permitting the latter to rise under the influence of the spring 77 and thus throw out the clutch in manner which has been heretofore described.

The mechanism provided by the present invention thus operates to completely terminate the action of the press and prevent damage to the parts in the event that two or more blanks are advanced simultaneously to the dies. Inasmuch as this may, and frequently does occur, due to the blanks sticking together, or, for any reason, not being fed in proper sequence, the efficiency of the machine is greatly increased by the use of the apparatus of our invention.

It is thought that the invention and many of its attendant advantages will be understood from the foregoing description, and it will be apparent that various changes may be made in the form, construction and arrangement of the parts without departing from the spirit and scope of the invention, or sacrificing all of its material advantages, the form hereinbefore described being merely a preferred embodiment thereof.

We claim:

1. In a punch press, and the like, the combination of die members, power mechanism for operating said die members, a clutch asso ciated with said power mechanism, a blank feed, a clutch control lever, means for holding said lever in position with the clutch engaged, and means operable by the simultaneous feeding of two or more blanks for automatically releasing said lever to cause disengagement of the clutch and stop operation of the press, said last-mentioned means comprising a movable member disposed in the path of the blanks, a pawl connected and movable with said member, means connecting said pawl with said clutch lever holding means and a movable ratchet adapted to actuate said pawl to release the clutch control lever when the latter is moved into engagement therewith by the action of a surplus blank or blanks in said blank feed.

2. In a punch press, and the like, the combination of die members, power means for operating said die members, a clutch associated with said power means, a clutch control lever, a member adapted to hold said lever in position with the clutch connected, spring means for moving said lever when released by said holding member to position with the clutch disconnected, and means for automatically moving the holding member to release said lever when more than one blank is advanced by said blank feed, said last-mentioned means comprising a rotary member in the path of the blanks and adapted to be actuated by the latter, a transverse rock shaft, a pawl loosely mounted on said shaft, a ratchet'rigidly mounted on said shaft, the pawl being brought into engagement with the ratchet by the action of surplus blanks on said rotary member, and means connecting said pawl with said clutch control lever holding means whereby movement of the pawl by said ratchet releases said control lever and stops operation of the press.

3. In a punch press having a driving clutch the combination of a stack holder, a suction device and vertically swinging arm for withdrawing blanks one by one from the bottom of said stackholder, a sliding feed bar for advancing the withdrawn blanks step-by-step to the punching station, devices operated by a moving part of the press for actuating said arm and feed bar in timed relation, an adjustable detecting stud mounted to be movable by an abnormal thickness of fed blanks, a movable socket member for said stud in which the stud is adjustable towards and from the path of the blanks, and means whereby the movement of the socket member causes the disengagement of said driving clutch.

4. In a punch press having a driving clutch the combination of a stack holder, a suction device and vertically swinging arm for withdrawing blanks one by one from the bottom of said stack holder, a sliding feed bar for advancing the withdrawn blanks step-by-step to the punching station, devices operated by a moving part of the press for actuating said arm and feed bar in timed relation, an adjustable detecting stud arranged on an angle which intersects the path of the fed blanks and mounted to be movable by an abnormal thickness of fed blanks, a movable sacket member for said stud in which the stud is adjustable towards and from the path of the blanks, and means whereby the movement of the socket member causes the disengagement of said driving clutch.

5. The combination of a treadle, means acting to elevate the same, a press-actuating clutch, a connection from the treadle to the clutch whereby the depression of the treadle causes the parts of the clutch to be engaged to actuate the press, means for holding the treadle depressed, means for feeding sheets to the operating station of the press, a detecting element at the path of the sheets which is actuated by a thickness of more than one sheet, said detecting element having sliding contact with the sheets, and means by which the movement of the detecting element causes the holding means of the treadle to be released from the latter.

' RONALD E. J. NORDQUIST.

MAGNUS E. WIDELL. 

